CN112813472A

CN112813472A - Local gold plating process for metal-glass packaging tube shell for hybrid integrated circuit

Info

Publication number: CN112813472A
Application number: CN202011590883.8A
Authority: CN
Inventors: 杨晨; 冯庆; 王宇飞; 杨文波; 罗育光
Original assignee: Xian Seal Electronic Material Technology Co Ltd
Current assignee: Xian Seal Electronic Material Technology Co Ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-05-18

Abstract

The invention relates to an electroplating method, in particular to a local gold plating process of a metal-glass packaging tube shell for a hybrid integrated circuit. The local gold plating process for the metal-glass packaging tube shell for the hybrid integrated circuit comprises the following process steps of: (1) pretreating, namely removing oil stains on the pipe shell, activating by hydrochloric acid, and removing oxide skin on the surface of the pipe shell; (2) respectively plating nickel on the shell and the core column integrally, then plating a layer of thin gold on the shell and the core column integrally, switching a hanger, only conducting electricity on the core column, plating gold on the core column independently, and plating the gold layer of the core column to the required thickness; (3) and switching the hanging tool, and covering a layer of electroplated nickel on the thin gold layer on the surface of the shell. The invention aims to overcome the defects in the background technology and provides a local gold plating process for a metal-glass packaging tube shell for a hybrid integrated circuit. The method is simple to operate, easy to control and suitable for large-scale production, and the obtained coating is stable in quality, good in appearance consistency and excellent in salt spray resistance.

Description

Local gold plating process for metal-glass packaging tube shell for hybrid integrated circuit

Technical Field

The invention relates to an electroplating method, in particular to a local gold plating process for a metal-glass packaging tube shell for a hybrid integrated circuit.

Background

The mixed integrated circuit is made up by using film-forming method to make thick film or thin film element and its interconnection line on the substrate, and on the same substrate the separated semiconductor chip, monolithic integrated circuit or miniature element are mixed and assembled, and then packaged. The metal-glass package provides a special hermetic environment, and the quality of the metal-glass package determines the stability of the whole device.

The metal-glass packaging tube shell has many leads and large volume, and the prior art adopts an integral nickel plating and gold plating process, which causes high cost. For the packaging process, nickel plating is mainly used for corrosion prevention, and gold plating is mainly used for ensuring the bonding strength and the weldability of the lead. Therefore, in the case of the hybrid integrated circuit package, on the premise of satisfying the use performance, in order to reduce the production cost to the maximum extent, only the lead part is required to be plated with nickel and gold, and the case only needs to be plated with nickel without being plated with gold. However, since the electrode potential of nickel is relatively negative to gold and the complexing strength of gold ions in gold plating solution on the market is not high, the nickel layer is very easy to form a replacement gold layer in the gold plating solution, the bonding force of the replacement gold layer is very poor, and the replaced nickel ions can pollute the gold plating solution, so that the research of a proper local gold plating process is very important.

At present, domestic research on a local gold plating process of a lead mainly focuses on three directions, one is that the potential difference between a nickel layer and gold is reduced through a gold plating solution additive, the technology is immature at present, the cost is high, and the stability of the gold plating solution is influenced; on the other hand, the method is realized by local shielding, and the process is complex, long in time consumption and difficult in large-scale production; the related process achieves the effect of local gold plating by removing the replacement gold by the gold removing liquid, and the method has extremely high requirements on the gold removing time and the parameters of the gold removing liquid, is difficult to operate and can influence the appearance of the coating of the packaging tube shell.

Disclosure of Invention

The invention aims to overcome the defects in the background technology and provides a local gold plating process for a metal-glass packaging tube shell for a hybrid integrated circuit. The method is simple to operate, easy to control and suitable for large-scale production, and the obtained coating is stable in quality, good in appearance consistency and excellent in salt spray resistance. In order to achieve the purpose, the invention comprises the following technical processes:

(1) pretreating, namely removing oil stains on the pipe shell, activating by hydrochloric acid, and removing oxide skin on the surface of the pipe shell;

(2) respectively plating nickel on the shell and the core column integrally, then plating a layer of thin gold on the shell and the core column integrally, switching hangers, only conducting electricity on the core column, plating gold on the core column independently, and plating the gold layer of the core column to the required thickness;

(3) and switching the hanging tool, and covering a layer of electroplated nickel on the thin gold layer on the surface of the shell.

The thickness of the integral electroplating thin gold layer in the step (2) is 0.06-0.10 μm.

The thickness of the electroplated nickel coating covering the surface of the shell in the step (3) is 1.5-2.0 μm.

And (2) completely removing oil stains on the pipe shell in the step (1), wherein alkaline cleaning chemical degreasing is firstly carried out, and then electric oil removal is further carried out.

The beneficial effects brought by the invention are as follows:

the method is simple to operate, easy to control and suitable for large-scale production, and the obtained coating is stable in quality, good in appearance consistency and excellent in salt spray resistance; and plating a layer of electroplated nickel on the shell and the core column integrally, plating a layer of thin gold on the shell and the core column integrally, then only conducting the core column, plating gold on the core column independently, and plating the gold layer of the core column to the required thickness, so that the gold plating workload is less and the cost is lower.

Detailed Description

The invention is further described in detail below with reference to the following examples:

the processes and features of the present invention are described in conjunction with specific embodiments, which are set forth to illustrate, but are not to be construed to limit the scope of the invention.

Example 1:

selecting a glass sealing tube shell of which the materials of the shell and the core column are 4J29 as an electroplating material, wherein the electroplating requirement is as follows: the shell core column is plated with nickel of 6-10 mu m integrally, and the gold plating of the core column is more than or equal to 1.0 mu m.

(1) And (3) pretreatment, namely performing alkali washing chemical oil removal on the pipe shell, further performing electrolytic oil removal, and then performing hydrochloric acid activation.

(2) And performing impact nickel, then plating a layer of uniform electroplated nickel on the shell and the core column integrally, wherein the thickness is not less than 4.5 mu m, performing pre-gold plating, and then plating a layer of thin gold of 0.06-0.10 mu m integrally. And switching the hanging tool, and plating gold on the core column to ensure that the thickness of the gold layer of the core column is not less than 1.0 mu m.

(3) And switching the hanging tool, and covering a layer of electroplated nickel with the thickness of 1.5-2.0 mu m on the thin gold layer on the surface of the shell, so that the local gold-plated tube shell meeting the requirement of the thickness of the coating can be obtained.

Example 2:

selecting a glass sealing tube shell of which the shell is made of 10# steel and the core column is made of 4J50 as an electroplating material, wherein the electroplating requirement is as follows: the shell core column is plated with nickel of 5-9 microns integrally, and the gold plating of the core column is more than or equal to 1.27 microns.

(2) And performing impact nickel, then plating a layer of uniform electroplated nickel on the shell and the core column integrally, wherein the thickness is not less than 3.5 mu m, performing pre-gold plating, and then plating a layer of thin gold of 0.06-0.10 mu m integrally. And switching the hanging tool, and only plating gold on the core column to ensure that the thickness of the gold layer of the core column is not less than 1.27 mu m.

Claims

1. A local gold plating process for a metal-glass packaging tube shell for a hybrid integrated circuit is characterized by comprising the following process steps:

(2) respectively plating nickel on the shell and the core column integrally, then plating a layer of thin gold on the shell and the core column integrally, switching a hanger, only conducting electricity on the core column, plating gold on the core column independently, and plating the gold layer of the core column to the required thickness;

2. The process of claim 1, wherein the thickness of the bulk gold plating layer in step (2) is 0.06-0.10 μm.

3. The process of local gold plating for a metal-glass package tube of a hybrid integrated circuit according to claim 1, wherein the thickness of the electroplated nickel layer covering the surface of the case in the step (3) is 1.5 to 2.0 μm.

4. The process of local gold plating on a metal-glass package tube shell for a hybrid integrated circuit according to claim 1, wherein the step (1) of removing oil contamination from the tube shell comprises alkaline cleaning chemical degreasing, and then further performing electrolytic degreasing.